‘City-killer’ asteroid had 20% chance of hitting Earth, Nasa feared but now it’s likelier to strike MOON in horror smash
NASA has said Earth will likely be spared by a deadly Big Ben-sized asteroid and predicts it could smash into the Moon instead in a dramatic collision.
The space agency feared the chance of a clash with Earth could reach an alarming 20% by April, but now says the rock will sail past.
Odds of the rock hitting the Earth stand at 1-in-37,000, but the Moon may not be so lucky.
The chance of the asteroid smashing into the Moon has risen to 1-in-55, and is expected to keep going up.
But a spokesman for Nasa said: “There still remains a very small chance for asteroid 2024 YR4 to impact the Moon.”
International Asteroid Warning Network manager, Dr Vishnu Reddy, added: “The most likely outcome is that also the Moon IP (impact probability) will peak at some point and then start to drop quickly.”
If the asteroid collided with the Moon, Earth would be largely unaffected.
Operations engineer for the University of Arizona’s Catalina Sky Survey, David Rankin, told the New Scientist: “There is the possibility this would eject some material back out that could hit the Earth, but I highly doubt it would cause any major threat.”
But he added that the collision would likely be “very visible” from Earth.
Nasa has repeatedly changed estimates on whether the asteroid will crash into Earth.
Astronomers first noticed that the asteroid was hurtling towards Earth in December – and it shot straight to the top of the risk list.
The YR4 asteroid was previously graded as level three on the Torino scale.
Binzel invented the Torino scale – the system used since 1999 to categorise potential Earth impact events.
This emergency level means: “A close encounter, meriting attention buy astronomers. Current calculations give a one per cent or greater chance of collision capable of localised destruction.”
Richard Binzel, a Professor of Planetary Science at MIT, revealed to The Sun why the odds have changed.
He said: “When we first discover an asteroid, we see only a tiny piece of its orbital path.
“Astronomers always check immediately to make sure that orbital path isn’t intersecting with Earth any time soon.
“The scientific challenge comes when that initial orbit check doesn’t immediately rule out an impact course.”
“It is not unusual for the probability numbers to bounce around a bit, simply because the amount of data in the first few weeks and months is usually quite limited.”
If YR4 – estimated between 130 and 300 feet wide – did strike Earth, it would pack a punch equivalent to eight million tonnes of TNT, scientists calculated.
It would cause a devastating impact, blowing a 1.2 mile-across crater into the Earth’s crust.
Physicists drew up a potential impact zone, cutting across some of the world’s most populated areas, including Bogotá, Abidjan, Lagos, Khartoum, Mumbai, Kolkata, and Dhaka.
But now scientists say there will be 167,000 miles of clear sky between the rock and our planet.
Nasa said the scare proved an “invaluable opportunity” to test Earth’s planetary defence procedures, as scientists came up with ideas to stop the killer asteroid.
Astronomers considered using nukes, solar lasers and rockets to knock the rock off course and break it into smaller pieces.
The asteroid will swing past Earth again in 2028, when final observations can be made ahead of the 2032 pass.
An asteroid of similar size to 2024 YR4 collides with Earth every few thousand years.